First Manufacturing Site of the Pelton Wheel

The invention was a splitter. Water jets hitting a cupped bucket dead centre lose energy fighting themselves; Lester Pelton's wheel divided each jet down a ridge and sent both halves out sideways, and the efficiency gain was enough to power hard-rock mining across the Sierra. It was first built commercially at George Allan's foundry on this site in 1879. High-head hydroelectric plants still use the design, largely unchanged, on every continent where the water falls far enough.

What the plaque says

The Pelton Water Wheel, first commercially manufactured here at George Allan's Foundry & Machine Works in 1879, was a major advancement in water power utilization and greatly advanced hard-rock mining. Its unique feature was a series of paired buckets, shaped like bowls of spoons and separated by a splitter, that divided the incoming water jets into two parts. By the late 1800s, Pelton Wheels were providing energy to operate industrial machinery throughout the world. In 1888, Lester Pelton moved his business to San Francisco, but granted continuing manufacturing rights to Allan's Foundry, where the wheels were manufactured into the early 1900s, when most local mines shifted to electric power.

Where it stands

Worth the stop nearby

• Nevada City — steps away
  Gaslamps, brick storefronts, and the Nisenan who are still fighting to be recognized on their own ground.
• Empire Mine State Historic Park — 4.5 mi
  The oldest, deepest, richest hard-rock gold mine in California, with 367 miles of flooded tunnels underneath.
• Malakoff Diggins State Historic Park — 9.6 mi
  A canyon washed out of a mountain by water cannon, and the lawsuit that ended hydraulic mining.

More markers nearby

• Nevada Theatre — steps away
• National Hotel — steps away
• South Yuba Canal Office — steps away
• Holbrooke Hotel — 3.8 mi